| Literature DB >> 35098383 |
Edoardo G Gronda1,2, Emilio Vanoli3,4, Massimo Iacoviello5, Stefano Urbinati6, Pasquale Caldarola6, Furio Colivicchi7, Domenico Gabrielli8.
Abstract
The kidney has a prominent role in maintaining glucose homeostasis by using glucose as a metabolic substrate. This occurs by generating glucose through gluconeogenesis, and by reuptaking filtered glucose through the sodium-glucose cotransporters SGLT1 and SGLT2 located in the proximal tubule. In recent studies, the administration of sodium-glucose cotransporters inhibitors demonstrated that inhibition of renal glucose reabsorption significantly reduces adverse renal events and heart failure exacerbations, in type 2 diabetic patients with and without cardiovascular damage as well as in advanced chronic kidney disease and heart failure patients with reduced ejection fraction with and without diabetes. The benefit was consistent throughout the different investigated clinical conditions, ameliorating overall patient outcome. The efficacy of sodium glucose cotransporters inhibitors was prominently linked to the limitation of renal damage as highlighted by the significant reduction on global mortality achieved in the studies investigating diabetic and not diabetic populations with advanced chronic kidney disease. Both studies were halted at the interim analysis because of unquestionable evidence of treatment benefit. In current review, we examine the role of SGLT2 and SGLT1 in the regulation of renal glucose reabsorption in health and disease and the effect of SGLT2 inhibition on clinical outcomes of populations with different cardiovascular conditions investigated with large-scale outcome trials.Entities:
Keywords: Cardiovascular death; Heart failure; Renal function; Sodium-glucose co-transporter 2 inhibitors; Type 2 diabetes mellitus
Year: 2022 PMID: 35098383 PMCID: PMC8801273 DOI: 10.1007/s10741-021-10211-9
Source DB: PubMed Journal: Heart Fail Rev ISSN: 1382-4147 Impact factor: 4.214
Fig. 1a, b (A) The kidney is an organ that promotes glucose sparing. In healthy adult humans, the kidney filters about 180 g daily. The filtered glucose is prematurely reabsorbed in toto (180 g/day) and glycosuria does not appear. The mechanism that allows the kidney to recover the glucose present in the glomerular filtrate is based on the coupled and integrated function of glucose and Na + transport from the peritubular vessel to the renal tubule. This mechanism benefits from the action of the sodium-glucose co-transporter type 2 (SGLT2) located in the tubule just below Bowman’s capsule in segment S1, associated with the sodium-glucose co-transporter type 1 (SGLT1) located in the underlying segment S2–S3. Eighty to 90% of the filtered glucose is reabsorbed by the SGLT2 enzyme and the remaining portion by the SGLT1 enzyme. (B) Glucose sparing in the kidney occurs via reabsorption in the proximal tubule. The action of the SGLT2-SGLT1 cotransporters is complementary, aimed at preventing glucose loss with urine. The reabsorption capacity of the co-transporters is higher than the activity they normally perform. In particular, the presence of a higher concentration of glucose in the filtrate leads to an increase in the activity of the co-transporter SGLT1, which has a high affinity for glucose, leading to an increase in the threshold of glycosuria. The figure shows how the coupling of SGLT2 and SGLT1 with the reciprocal glucose transporter GLUT2 and GLUT1, compose a single mechanism, functional to the complete recovery of glucose present in the filtrate. This mechanism is coupled to Na + recovery, maintaining a glucose to Na + ratio of 1:1 for SGLT2 and 1:2 for SGLT1. Energy for reabsorption of molecules is provided by the Na + /K + ATPase-dependent pump that is located in the basolateral membrane of the tubule. [2]
Reproduced with permission from Gronda et al.
Fig. 2Abbreviations and acronyms: RCO = renal composite outcome (doubling creatinine or kidney replacement therapy or cardiovascular-renal mortality). CV = cardiovascular mortality. HHF = hospitalization for heart failure. CVOT = cardiovascular outcome trial. T2DM = Type 2 diabetes mellitus. SGLT2i = sodium glucose cotransporter 2 inhibitors. HFrEF = heart failure with reduced ejection fraction. CKD = chronic kidney disease. a Three large CVOTs investigated SGLT2is effects in T2DM population with different CV risk as expressed by the proportion of subjects in secondary prevention ranging from 100 to 39%. Despite the disparity of disease severity, SGLT2i administration generated a rather homogenous HR reduction for CRO while HHF and CV mortality consistently declined in studies with the increasing proportion of patients enrolled for primary prevention. b Two large trials explored SGLT2i effects in HFrEF patients. The two investigated populations had different disease severity being more advanced with more severe kidney impairment in the EMPEROR Reduced in comparison to DAPA-HF that was based on larger population study design with relatively longer follow up (16 vs 19 months). The studies provide complimentary results. In both investigations, HHF decreased at the same extent, while CV mortality was affected with statistical significance only in DAPA HF, and CRO plus renal function worsening displayed statistically significant decrease only in EMPEROR Reduced trial. In EMPEROR Reduced “worsening of renal function” is indicated as “Mean slope of change in eGFR ml/min/1.73 m2 per year” and is favored by placebo administration. c In studies conducted on patients with CKD with and without T2DM, characterized by low glomerular filtration (lower limit eGFR > 25 mL/min/1.73 m2) with and without albuminuric nephropathy, the administration of canaglifozin (CREDENCE) and dapaglifozin (DAPA-HF) resulted in an early and unequivocal benefit on all the predefined envisaged outcomes, requiring the early closure of the two studies. On note the global mortality was decreased in almost statistically significantly fashion in CREDENCE while it was definitely significantly decreased in DAPA CKD
Data in the table provide comparison of the studies population size analyzed in the manuscript, addressing the proportion of enrolled subjects with eGFR < 60 mL/min/1.73 m2 on the basis of adopted eGFR calculation formula. The data emphasize the differences among investigated cohorts did not affect the reported outcomes concordance
| Study | No. of enrolled patients | eGFR calculation formula |
|---|---|---|
EMPA-REG OUTCOME15 (Empaglizozin) NEJM 2015 | 7020 26% | Modification of Diet in Renal Disease (MDRD) equation |
CANVAS16 (Canaglifozin) NEJM 2019 | 10,142 20.1% | Chronic Kidney Disease Epidemiology Collaboration formula |
DECLARE TIMI 5817 (Dapaglifozin) NEJM 2017 | 17,160 7% | Cockcroft and Gault formula MDRD equation Chronic Kidney Disease Epidemiology Collaboration equation (CKD-EPI) |
DAPA HF24 (Dapaglifozin) NEJM 2019 | 4744 40% | CKD-EPI |
EMPEROR Reduced25 (Empaglizozin) NEJM 2020 | 3730 48% | CKD-EPI |
CREDENCE35 (Canaglifozin) NEJM 2019 | 4401 60% | CKD-EPI |
DAPA CKD36 (Dapaglifozin) NEJM 2020 | 4304 89% | CKD-EPI |